THE OEANGE IN CALIFORNIA — CULTIVATION. 113 



according to the best practice the deepening of cultivation 

 should be gradual, and the implement should never run deeper 

 than fifteen inches. One must remember that the really- 

 serious loss in sudden deep cultivation comes from the destruc- 

 tion of thousands of fibrous roots that grow from the hundreds 

 of laterals branching from the large main roots. 



If a plow is run to a depth of one foot, in three furrows, 

 between the rows, and water percolates slowly for a long time 

 through these furrows, no need can arise for a subsoiler. 

 " Irrigation hardpan" within reach of the plow simply shows, 

 as has been said, that too shallow and too uniform cultivation 

 has been practiced. In that case the entire surface should be 

 thoroughly broken up, and irrigation in deep furrows after 

 this will restore the proper conditions. 



Experience also shows that when the water is slowly run in 

 deep furrows for a long time and the greater part of the surface 

 is kept dry and is deeply cultivated, better results are obtained 

 than when the basin or block method, or even the shallow-furrow 

 plan, is used, even though they are followed by deep cultiva- 

 tion. When the water is applied below the first foot of soil, 

 and the soil above is kept comparatively dry, there is nothing 

 to attract the roots to the surface; and when the water is thus 

 applied, a team can be driven along the dry strips of land 

 between the furrows, and with a harrow or other appliance the 

 dry soil can be dragged into the wet furrows, to lessen the 

 evaporation, immediately after the irrigation water is turned 

 off. By any other system, it is absolutely necessary to wait at 

 least twelve hours, and sometimes much longer, before a team 

 can be driven over the ground. Then, too, when a soil irri- 

 gated by these more wasteful methods has been cultivated, it is 

 still moist near the top, and is soon filled with a mass of new 

 roots so close to the surface that they must be destroyed. 



Water applied to the soil sinks and spreads. Some of it is 

 being taken up by the still dry soil underneath and at the 

 sides long after the last drop is visible. Some of it, too, is 

 being drawn back to the surface, and thence evaporated into 

 the warm air. Irrigation after sundown has some distinct 

 advantages, if the water can be handled. Sub-irrigation upon 

 soils adapted to its use is the ideal system of applying water, 

 and greatly lessens waste. Orange roots will not enter a pipe- 

 line unless it is full of water all the time. If the pipe is on a 

 8c 



